Optical module connector adaptor

ABSTRACT

An adapter  5  for an optical connector comprises a pair of wall portions  55   a  and  55   b  on a mounting surface  56   a . The structure allows the adapter to accommodate an optical connector  4  inserted from a direction vertical to the mounting surface  56   a , and allows the adapter to accommodate an optical connector  7  inserted along a predetermined axis  8 . On this account, it is possible to insert the connector  7  along the predetermined axis  8  to the housed optical connector  4 . Since the optical connector  4  is mated to and demated from the optical connector  7  in this sort of adapters, force applied to an optical module  2  is decreased in mating/demating the connector. An optical module product  9  includes the optical module  2 , a coated optical fiber  3 , the optical connector  4 , and the optical connector&#39;s adapter  5 . An optical module mounting substrate product  1  includes the optical module product  9  and a substrate  10  for mounting thereon the optical module  2  and the adapter  5  for optical connectors.

TECHNICAL FIELD

The present invention relates to an adapter for accommodating an opticalconnector, an optical module product including an optical connector, anadapter for the optical connector and an optical module, and an opticalmodule mounting substrate product including the optical module productmounted onto a substrate.

BACKGROUND ART

A receptacle type optical module is known as an optical module. Theoptical module makes conversion such as opto-electric conversion, i.e.,O/E conversion, or electro-optic conversion, i.e., E/O conversion. Forthe conversion, an optical fiber is optically connected to the opticalmodule so as to receive and provide optical signals. This connection ismade through a detachable/attachable connector.

DISCLOSURE OF THE INVENTION

As results of study on optical module products each including theoptical module, the present inventors have found following problems. Areceptacle type optical module includes a connector portion therein. Anoptical connector is directly mated to and unmated from this connectorportion while connecting an end of an optical fiber. Thus, in thereceptacle type optical module, external forces may be directly appliedto the optical module itself when the optical connector is attachedthereto or detached therefrom. The present inventors have found that theexternal forces may damage components in the optical module.

It is, therefore, an object of the present invention to provide anadapter, allowing external forces applied to an optical module todecrease when an optical connector is mated thereto or demated therefromwith a coated optical fiber connected to the optical connector, for anoptical module connector, an optical module product including an opticalmodule connector, and an optical module mounting substrate product onwhich the optical module product is mounted.

The adapter for an optical connector according to the present inventioncomprises a bottom portion and first and second wall portions. Thebottom portion has a mounting surface that extends along a predeterminedaxis, and the mounting surface is provided so as to mount first andsecond optical connectors thereon. The first and second wall portionshave respective inner wall surfaces thereof, each extending along apredetermined axis. The first and second wall portions are provided onthe mounting surface such that one inner wall surface faces the other.

Preferably, the adapter for an optical connector can be applied to anoptical module product comprising an optical module, a coated opticalfiber, and a first optical connector. One end of the coated opticalfiber is connected to this optical module. The other end of the coatedoptical fiber is connected to the first optical connector.

The adapter has a structure, providing the wall portions on the mountingsurface, that makes it possible to accommodate the first opticalconnector provided along the direction vertical to the mounting surfaceand to accommodate the second optical connector provided along thepredetermined axis. Thus, the second connector can be inserted in thepredetermined axis direction to the accommodated first opticalconnector. The first optical connector is connected to the opticalmodule through the coated optical fiber. Since the second opticalconnector is mated to and demated from this first optical connector, theexternal forces applied to the optical module, is decreased in matingand demating.

The bottom portion and the first and second wall portions are arrangedto provide first and second opening portions. The first opening portionis opened in the direction vertical to the mounting surface so as toreceive the first optical connector therefrom, and the second openingportion is opened in the predetermined axial direction so as to receivethe second optical connector therefrom.

Since the adapter has a structure having the first opening portion andthe second opening portion, the first connector can be inserted throughthe first opening portion of the adapter onto the mounting surface andthen can be accommodated on the mounting surface while it is guided byboth inner wall. The second connector is inserted through the secondopening portion and then is introduced along both inner walls and themounting surface of the adapter. Since the second connector is insertedwhile being guided by the adapter, the second connector can be mated tothe first optical connector without damaging the coated optical fiberconnected to the accommodated first optical connector.

The adapter further comprises a stopper. The stopper is provided so asto restrict a range where the first optical connector can move in thepredetermined axial direction.

The stopper of the adapter defines a range within which the firstoptical connector can be disposed with respect to the predeterminedaxial direction. Specifically, even if the first optical connector ispushed by the second optical connector when the second optical connectoris inserted along the predetermined axis to the adapter, the stopperrestricts the movement range of the first optical connector. Forexample, since the stopper defines a limit point to which the firstoptical connector can move, the stopper can suppress a so-called ferruleback phenomenon of an optical connector. Since the stopper can reducethe force applied to the coated optical fiber by the moving firstoptical connector, the stress that may be applied to the coated opticalfiber can be decreased. Further, it is ensured that the second connectoris mated to the first optical connector.

In the adapter for an optical connector according to the presentinvention, the stopper can be provided such that the position of thestopper can be adjusted with respect to the predetermined axisdirection. If the position of the stopper is adjusted, the adapter canbe applied to various types of optical connectors. The position of theattached stopper can be adjusted in accordance with the configurationsof the first and second optical connectors. Further, the adapter for anoptical connector according to the present invention can be providedwith at least one of a recess and a protrusion provided so as to adjustthe position of the stopper with respect to the predetermined axialdirection. The recess and protrusion above can be provided on each ofthe inner wall surfaces of the first and second wall portions. Therecess and protrusion above also provide a simple structure, whichenables the recess and/or the protrusion to engage with the stopper,that can restrict the movement of the optical connector. This simplestructure results in the adapter having high reliability. Furthermore,when the recess and/or protrusion are employed, the stopper can bepositioned with high precision in accordance with the positions of therecess and protrusion.

The adapter for an optical connector according to the present inventionfurther comprises a third wall portion, extending in a directionintersecting with the predetermined axis, which is in contact with thefirst and second wall portions and the bottom portion.

The third wall portion functions as a stopper to the optical firstconnector. The third wall portion can include a cut portion. This cutportion is provided so as to introduce and guide the coated opticalfiber connected to the first optical connector.

The adapter for an optical connector according to the present inventionfurther comprises a lid, supported by the first and second wallportions, which can be provided so as to face the mounting surface. Thislid can be provided so as to cover the first opening portion.

This lid, together with the mounting surface, can define the position ofthe optical connector with respect to the direction vertical to themounting surface. On this account, it is possible to decrease bending ofthe optical fiber that may be caused by movement, in the adapter, of theconnected or non-connected optical connector. The lid can protect theoptical connectors arranged in the adapter, for example, the lid canprevent the optical connectors from directly contact with parts disposedaround the optical connectors, and can provide dust-tight adapter. Thelid can protect the optical connector against heat in a step of reflowsoldering in manufacturing a optical module product.

In the adapter for an optical connector according to the presentinvention, the bottom portion has a latch portion. The latch portion isprovided so as to extend opposite to the direction, with respect to themounting surface, in which the first and second wall portions extend.The bottom portion may also include one or more latch portions. Thelatch portion facilitates the attachment of the adapter to thesubstrate.

Further, the adapter for an optical connector according to the presentinvention may have one or more additional features as described below.

In the adapter for an optical connector of the present invention, thelid may include a plurality of leg portions extending from the oppositesides of the lid. Each of the plurality of leg portions can include aprojection engaging with the bottom portion of the adapter. Each of thefirst and second wall portions can include, on the respective outersurfaces of the wall portions, guide grooves for guiding the pluralityof leg portions of the lid. This lid can have an inner wall surfaceprovided so as to face the mounting surface. This inner wall surface caninclude a protruding portion so as to position the first and secondconnectors with respect to the direction vertical to the mountingsurface. The inner wall surface can also include a guide portion forguiding the second connector with respect to its insertion direction.Further, the bottom portion has a plurality of latch portions, extendingalong an axis perpendicular to the mounting surface, on a bottom surfaceopposed to the mounting surface. Each of the plurality of latch portionsincludes a projection provided so as to be latched in a substrate to beattached.

An optical module product of the present invention comprises an opticalmodule, an adapter for an optical connector, an optical fiber and afirst optical connector. The optical module makes conversion in at leastone of the following directions: the conversion from electric signals tooptical signals; and the conversion from optical signals to electricsignals. The optical connector is accommodated in the adapter. Theoptical fiber has a first end portion connected to the optical moduleand a second end portion connected to the optical connector. The opticalmodule product according to the present invention has one of theadapter's configurations that has already been described above and willbe described below.

According to the optical module product, the adapter can hold theoptical connector attached to one end of the optical fiber, the otherend of which is connected with the optical module. The adapter canreduce the magnitudes of forces, such as bending forces, applied to theoptical fiber.

For example, since the first optical connector can be provided on themounting surface of the adapter in the direction vertical to themounting surface through the first opening portion, the forces appliedto the optical fiber can be reduced. Since the second optical connectoris inserted through the second opening portion along the predeterminedaxis, i.e., in a direction of the optical axis of the first opticalconnector, to mate the first connector, these optical connectors can beeasily mated to each other.

In the optical module product according to the present invention, theoptical fiber can include a coating layer. The coating layer protectsthe optical fiber against forces that act thereon when the optical fibercontacts with peripheral components or the like. The coating layer canalso protect the optical fiber against heat in a reflow soldering stepof optical module product manufacture. Since the coating layer providesrigidity in the optical fiber, the amount of the optical fiber bendingcan be decreased even if forces is exerted on the optical fiber.

In the optical module product of the present invention, the coated layermay include a heat-shrinkable tubing adhered to the side surface of theoptical fiber. The heat-shrinkable tube is easily adhered to the opticalfiber to form the adhered coating layer. The heat-shrinkable tubing canalso protect the coated optical fiber against heat added in the reflowsoldering step because of the excellent heat resistance of theheat-shrinkable tubing. If the heat-shrinkable tubing is also providedaround a portion of the optical fiber where bending is apt to occur,such as the connection portion of the optical fiber connected with theoptical connector or optical module, the bending of the optical fibercan be decreased.

An optical module mounting substrate product according to the presentinvention comprises one or more optical module products and a substrate.The substrate has a conductive wiring layer. An optical module and anadapter are mounted on the substrate. The optical fiber has a first endportion connected to the optical module and a second end portionconnected to an optical connector. The optical connector is accommodatedin the adapter. The adapter may has one of the configurations that hasalready been described above and will be described below.

Since the second optical connector is mated to and unmated from thefirst connector that is accommodated in the adapter with the opticalmodule connected to one end of the first connector, the accommodationprevents force from being directly exerted to the optical module in themating and unmating it. This arrangement can decrease variation incharacteristics of the optical module caused by the force exerted thereto in mating the connectors. This allows the optical module to keepexcellent characteristics for a long term.

The adapter receives the optical connector provided in the directionvertical to its mounting surface. This configuration makes it possibleto shorten the length of the optical fiber to the same degree as thedistance between the adapter and the optical module on the substratewhile connecting the optical module with the optical connector. It ispossible to reduce the length of the optical fiber necessary forarranging the optical connector in the adapter. Thus, the optical fiberdoes not have a surplus length that becomes unnecessary after theconnectors are mated with each other. Since the optical fiber has nosurplus length, this saves an area on the substrate required for placingthe optical fiber tied together.

In the optical module mounting substrate product according to thepresent invention, an interval between the optical module and theadapter can be not less than 10 mm and not more than 40 mm. Thisdistance is suitable for increasing the mounting density of thesubstrate.

In the optical module mounting substrate product according to thepresent invention, the optical module, the optical connector, theoptical fiber and the adapter for the optical connector can be providedalong the optical axis of the optical module product.

The optical module mounting substrate product according to the presentinvention includes 16 optical module products. Each of the opticalmodule products is provided so as to face one side of the substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing an optical module product, anoptical module mounting substrate product, and optical connectorsaccording to a first embodiment.

FIG. 2 is a side view showing the optical module product, the opticalmodule mounting substrate product, and the optical connectors accordingto the present embodiment.

FIG. 3A is a plan view showing the optical module product including anoptical connector adapter in which the optical connector isaccommodated, the optical module mounting substrate product, and anotheroptical connector.

FIG. 3B is a view showing a positioning portion.

FIG. 4 is a plan view showing the optical module product to which theoptical connector is connected.

FIG. 5 is a sectional view showing an optical connector, an opticalmodule product including an optical connector adapter accommodatinganother optical connector mated to the optical connector, and an opticalmodule mounting substrate product.

FIG. 6 is a plan view showing a modification of the optical connectoradapter.

FIG. 7 is a plan view showing a modification of the optical connectoradapter.

FIG. 8 is a plan view showing a modification of the optical connectoradapter.

FIG. 9 is a plan view showing a modification of the optical connectoradapter.

FIG. 10 is a perspective view showing an optical module product, anoptical module mounting substrate product, and an optical connectoraccording to a second embodiment of the present invention.

FIG. 11 is a side view showing the optical module product, the opticalmodule mounting substrate product, and the optical connector accordingto this embodiment.

FIG. 12 is a plan view showing the optical module product to which theoptical connector is connected.

FIG. 13 is a schematic view showing an optical module mounting substrateproduct according to a third embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described withreference to the drawings. The same or like portions are designated bythe same reference numerals to omit the repeated explanation.

A first embodiment of an optical module member of the present inventionwill be described with reference to FIGS. 1 to 5.

With reference to FIG. 1 and FIG. 2, an optical module mountingsubstrate of this embodiment is shown. An optical module mountingsubstrate product 1A of this embodiment comprises an optical moduleproduct 9A and an optical module mounting substrate (hereinafterreferred to as a substrate) 10. The optical module product 9A comprisesan optical module 2, an coated optical fiber 3, an optical connector 4,and an adapter for the optical connector (hereinafter referred to as anadapter) 5A. The adapter 5A can include a cover 6A. The optical module 2and the adapter 5A, included in the optical module product 9A, aremounted on the substrate 10. These drawings also show another opticalconnector 7A to be mated to the optical connector 4.

A printed circuit board can be used as the substrate 10. The printedcircuit board comprises an optical module mounting surface 13, a rearsurface 14, and a wiring layer such as printed wiring, between thesesurfaces. Other electronic parts are also mounted on this substrate 10,and the electronic parts are electrically connected to each otherthrough the printed wiring. The optical module 2 is also electricallyconnected to these electronic parts.

The substrate 10 has a plurality of through holes 11 for attaching theoptical module 2, and a plurality of mounting holes 12 for attaching theadapter 5A. Terminals 20 of the optical module 2 are soldered to thesubstrate 10 with the terminals 20 inserted in the through holes 11.When the terminals 20 are soldered to the holes 11, the optical module 2is electrically connected to the printed wiring of the substrate 10.Electrical signals are entered to and provided from the optical module 2through the through holes 11.

The optical module 2 makes at least one of the following conversion:conversion from optical signal to electrical signal; and conversion fromelectrical signal to optical signal. For the conversion, the opticalmodule 2 includes at least one of a light receiving device, such as asemiconductor light receiving element, and a light emitting device, suchas a semiconductor light emitting element. As the semiconductor lightreceiving element, a photodiode is used, and as the semiconductor lightemitting element, a semiconductor laser and a light emitting diode areused. This optical device is optically coupled to an optical fiberincluded in the coated optical fiber 3.

The optical module 2 has a molding resin 22 provided so as to mold theoptical device. A bottom surface 22 a of the molding resin 22 isprovided with the terminals 20. The molded optical device can convertelectrical signals, entered through the terminals 20, into opticalsignals to provide the converted signals to the coated optical fiber 3.The molded optical device can also convert optical signals, enteredthrough the coated optical fiber 3, to electrical signals to provide theconverted signals to the pins 20. The optical module 2 is not limited tothe pin type optical module shown in this embodiment, and other types ofoptical modules, such as a flat package type optical module, is alsoused as the optical module 2.

The coated optical fiber 3 is taken out of an end surface 22 b of themolding resin 22 in the optical module. In this embodiment, a multifilament multi-filament tape fiber is adopted as the coated opticalfiber 3. The coated optical fiber 3 has one end connected to the opticalmodule 2 and the other end attached to the optical connector 4.

The coated optical fiber 3 is covered with a coating layer 30 such as aheat-shrinkable tubing on the side surface thereof. The coating layer 30is adhered to the side surface of the optical fiber 3. After the coatedoptical fiber 3 is inserted in the heat-shrinkable tubing 30, heat isadded to the heat-shrinkable tubing 30 to contract the heat-shrinkabletubing 30. Then, the heated tube 30 is adhered to the side surface ofthe optical fiber 3 to form a protecting layer. The coating layer 30prevents the optical fiber from directly contacting components disposedaround the coated optical fiber 3, and protects the coated optical fiber3 against the a tradiated directly thereto. The heat-shrinkable tubing30 is adhered to the side surface of the optical fiber to providerigidity to the coated optical fiber 3, whereby the coated optical fiber3 can not easily bent. The protecting layer 30 can also coat aconnection portion of the optical fiber 3 connected with the opticalconnector 4 and a connection portion of the optical fiber 3 connectedwith the optical module 2, respectively. Specifically, one end of theheat shrinkable tubing 30 is attached so as to cover a boot 41 of theoptical connector 4 as well. Thus, the protecting layer prevents thecoated optical fiber 3 from bending at the connection portion betweenthe optical connector 4 and the optical fiber 3 that is apt to be benteasily.

The optical connector 4 as shown in FIGS. 1 to 5 is an MT typeconnector. The optical connector 4 is used in combination with theoptical connector 7A to be connected thereto. In this embodiment, theconnectors 4 and 7A are provided so as to be used as push-on typeoptical connectors.

One or more filaments of the coated optical fiber are arranged and arefixed in the optical connector 4. The coating resin is removed at an endportion of the coated optical fiber 3 so as to expose the side surfacesof the coated optical fibers. The end faces of the optical fibers arepositioned at an end surface 40 a of the optical connector 4. The endsurface 40 a is opposed to the end portion of the optical connector 4which the optical fiber 3 reaches. A pair of guide pins 42 protrude fromthe end surface 40 a of the optical connector 4 to position it withrespect to the other optical connector 7A. The pair of guide pins 42 aredirected toward the optical axis direction of the optical fiber arrangedin the optical connector 4. Respective guide pins 42 are provided toform separate members from a ferrule covering the optical fiber, and canbe made of, for example, metal. However, the optical connector is notlimited thereto. The optical connector 4 has an upper surface 40 b, abottom surface 40 c, and a pair of side surfaces 40 d and 40 e, eachprovided along the optical axis direction. The adapter 5A has a bottomportion 56 extending along a predetermined axis The bottom portion 56can be a plate-like support extending in one direction. The bottomportion 56 has a mounting surface 56 a provided so as to mount theoptical connectors 4 and 7A thereon. The bottom portion 56 also has, onthe mounting surface 56, a pair of protrusions 56 b and 56 c extendingin the longitudinal direction of the adapter. The protrusions 56 b and56 c support not only the bottom surface 40 c of the optical connector 4but also the bottom surface of the optical connector 7A. To supportthem, the pair of protrusions 56 b and 56 c extend from one end to theother end of the bottom portion 56. Each protrusion has a shape providedso as to fit the optical connectors 4 and 7A, and can include a recessand a protrusion such as a protruding portion 56 d. Since the opticalconnectors 4 and 7A are accommodated in the adapter 5A while supportedon the protrusions 56 b and 56 c so as to provide space between themounting surface 56 a and the bottom surface 40 e of the opticalconnector. This gap can decrease heat transferred from the substrate 10to the optical connectors 4 and 7A. That is, the gap works as a heatinsulating layer.

A pair of wall portions 55 (55 a, 55 b) extend along a predeterminedaxis on the mounting surface 56 a of the bottom portion 56. The pair ofwall portions 55 a and 55 b are provided so as to face their inner wallsurfaces 55 c and 55 d with each other. The housed optical connectors 4and 7A are arranged between the inner wall surfaces 55 c and 55 d. Forexample, the optical connector 4 is guided by the pair of side surfaces40 d and 40 e when it is accommodated. The pair of wall portions 55determine the direction of the optical axis of the optical fiber in thepair of optical connectors 4 and 7A to be connected.

The adapter 5A may has a third wall 58 on the mounting surface 56 a. Thewall portion 58 is arranged at one end of the bottom portion 56. Thefirst to three sides of the wall portion 58 reach the bottom portion 56and the pair of wall portions 55, respectively. The wall portion 58 hasa notched portion 58 a. The notched portion 58 a is provided so as toform a recess cut from the fourth side of the wall portion 58 toward themounting surface 56 a, and in this embodiment, it reaches the mountingsurface 56 a. The optical fiber 3, connected to the connector 4, entersthrough this cut 58 a. The optical fiber 3, entering through the cutportion 58 a, is introduced unforcibly to the optical connector 4mounted on the mounting surface 56 a.

The adapter 5A is formed of a resin exhibiting heat resistance, such asPPS (polyphenylene sulfide). The adapter 5A resists, for example, atemperature at which it is exposed in a soldering step.

The depth of the cut 58 a is determined with respect to the bottomportion 56 such that the optical fiber 3 is arranged almost parallelwith the substrate 10 when the optical connector 4 is mounted in theadapter 5A with the optical module 2 and the adapter 5A mounted on thesubstrate 10. Besides, protrusions consisting of portions 56 b, 56 c and56 d are provided on the mounting surface 56 a of the bottom portion 56so as to be fitted with the shapes of the optical connectors 4 and 7, sothat the optical axis direction of the mounted optical connectors 4 and7A becomes almost parallel with the substrate 10.

The first and second wall portions 55 a and 55 b and the bottom portion56 of the adapter 5A are provided so as to define an accommodation forthe optical connectors 4 and 7A. A first opening portion 50 is providedbetween the pair of wall portions 55 a and 55 b of the adapter 5A so asto be opened in the direction vertical to the mounting surface 56 a. Theoptical connector can be received through the adapter 5A. Besides, asecond opening portion 51 is provided between the pair of wall portions55 a and 55 b of the adapter 5A. The second opening portion 51 is openedin a direction in which a predetermined axis 8 (shown in FIG. 2)extends. The second opening portion 51 is provided on one of theopposite side edges of the adapter 5A and the other side edge faces theoptical module 2. The adapter 5A can receive the optical connector 7Athrough this opening portion 51. The optical connector 4 can be,therefore, introduced through the first opening portion 50 so as to beaccommodated in the adapter, and then the optical connector 7A can beinserted through the second opening portion 51 toward the opticalconnector 4. This insertion direction is the same as the optical axisdirection of the held optical connector 4.

The adapter 5A has a plurality of latch portions 57 extending in thedirection opposite to the wall portion 55 with respect to the mountingsurface 56 a. With reference to FIGS. 1 and 2, the respective latchportions project at four corners of the bottom portion 56. Respectiveprotrusions 57 a are provided at one end of the latch portions 57. Eachof the protrusions 57 a has a taper surface 57 b and a latch surface 57c. The taper surface 57 b is provided to come in contact with themounting hole 12 in which the latch portion 57 is to be inserted whenthe adaptor is mounted on the substrate. The latch surface 57 c isprovided to face the rear surface 14 of the substrate 10 after the latchportion 57 has been inserted in the mounting hole 12.

The adapter 5A can be moved in the direction of Arrow E shown in FIG. 1while the latch portions 57 of the adapter 5A are positioned in themounting holes 12. The adapter 5A is pushed to the substrate 10, so thatthe taper surface 57 b comes in contact with the edge of the mountinghole 12. The substrate 10 exerts the respective latch portions 57, sothat the latch portions are bent inward. When the taper surface 57 bovercomes the mounting hole 12 of the substrate 1, the latch portions 57return to the respective original shapes, so that the latch portion 57is engaged in the mounting hole 12. In this arrangement, the latchsurface 57 c faces the rear surface 14 of the substrate 10. When thelatch portions 57 of the adapter 5A are latched, the adapter 5A ismounted on the substrate 10.

In the adapter 5A, the bottom portion 56 has a supporting portion 56eprovided on the rear surface opposite to the mounting surface 56 a onwhich the wall portions 55 a and 55 b are provided. The supportingportion 56 e is arranged between the substrate 10 and the bottom portion56. The support member 56 e includes a supporting plate that extendsaround one end of the adapter 5A, then extends along the bottom portion56 in the longitudinal direction, and then reaches the bottom portion 56around the other end thereof. The supporting portion 56 e hasa-predetermined height so that a space is provided between the substrate10 and the bottom portion 56. This space is provided so as to decreasethermal conduction from the substrate 10 to the adapter 5A.

The adapter 5A includes a guide member 53. The guide member 53 has apair of arm portions 53 a extending in a predetermined direction, and abridge portion 53 b extending in a direction intersecting with thepredetermined direction An end of each arm portions 53 a includes anengaging portion 54 protruding inward. The adapter 5A also has a stopper52, which is secured thereto with the stopper 52 positioned in theadapter 5A. When the guide member 53 reaches the stopper 52, it cannotmove over the stopper 52. That is, the stopper 52 defines a range inwhich the guide member 53 can move in the direction in which the opticalfiber 3 extends.

The stopper 52 is provided between the pair of wall portions 55. Therespective inner surfaces 55 c and 55 d of the wall portions 55 havemeans for positioning the stopper 52 thereon.

The adapter 5A has positioning portions 55 e and 55 f including at leastone of protrusions and recesses on the inner surfaces 55 c and 55 d.

FIG. 3A is a view showing the optical module product 9A and the opticalmodule mounting substrate product 1A. FIG. 3B is an magnified view ofthe stopper 52 provided in a positioning portion 57. The positioningportions 55 e and 55 f may include, for example, protrusions 55 e and 55f provided at predetermined intervals, and may include the recesses 55 eand 55 f arranged periodically.

The stopper 52 has engaging portions 52 a and 52 b, on both endsthereof, engaged in the positioning portions 55 e and 55 f provided onthe inner surfaces 55 c and 55 d. Each of the engaging portions 52 a and52 b has a shape corresponding to the protrusions and/or recesses of thepositioning portions 55 e and 55 f. For example, each of the engagingportions 52 a and 52 b may include a shape corresponding to theprotrusions 55 e and 55 f provided at predetermined intervals, and mayinclude a shape corresponding to the recess portions 55 e and 55 farranged periodically.

A range in which the positioning portions 55 e and 55 f should bearranged is determined so as to correspond to the range in which theoptical connector 4 should be positioned. The stopper 52 is secured at aposition associated with that of the optical connector 4. The followingprocedure shows securing steps. The stopper 52 is positioned at aposition, within the positioning portions 55 e and 55 f, correspondingto the position at which the optical connector 4 should be. The stopper52 is pushed toward the mounting surface 55 a along the positioningportions 55 e and 55 f. After this pushing, the stopper 52 is haspositioned with respect to the direction of the optical axis of theoptical connector 4. Since the stopper 52 is movable in the directionvertical to the mounting surface 55 a, the stopper 52 can be pulled outin this direction. The position of the stopper 52 can be easily adjustedwith respect to the optical axis direction by changing the position ofthe engagement between the engaging portions 52 a and 52 b and thepositioning portions 55 e and 55 f. The guide member 53 is arrangedwhile coming in contact with the positioned stopper 52.

The guide member 53 has the engagement projection 54 provide done acharm portion 53 a. The engagement projection 54 is engaged in anengagement portion 74 of the optical connector 7A, so that the opticalconnector 7A is mated with the optical connector 4. To this end, theengagement protrusion 54 has a taper surface 54 a and a latch surface 54b. When the optical connector 7A is pushed in to the direction of ArrowA (shown in FIG. 1), the taper surface 54 a is brought into contact witha taper surface 74 a of the engagement portion 74. The gradual pushingcauses the engagement portion 74 to bend inward. When the taper surface74 a of the optical connector 7A surmounts the engagement projection 54,the taper surface 74 a releases the engagement projection 54, so thatthe respective engagement portions 74 return to their respectiveoriginal shapes. As a result, the engagement portion 74 has been engagedin the guide projection 54. In this configuration, the latch surface 54b of the engagement member 53 faces the latch surface 74 b of theoptical connector 7A. When the engagement portion 74 of the opticalconnector 7A is latched by the engagement projection 54 of theengagement member 53, the optical connector 7A is secured to the guidemember 53.

The bridge portion 53 b connects the pair of arm portions 53 a Thebridge portion 53 b connects the arm portions 53 a of the guide member53 such that the optical connector 4 is provided between the sidesurfaces 40 d and 40 e of the arm portions 53 a. Since the innersurfaces 53 c of the respective arm portions 53 a face with each other,both the inner surfaces 53 c can guide the optical connector 4. Sincethe optical fiber 3, connected to the optical Connector 4, is agesarranged between the bridge portion 53 b and stopper 52, and themounting surface 56 a in cooperation with, the positional range of theoptical fiber 3 is restricted with respect to the direction verticalnormal to the mounting surface 56 a.

Referring to FIG. 1 and FIG. 2 again, the adapter 5A comprises a cover6A provided so as to cover the first opening portion 50 therewith. Thecover 6A has a lid portion 60, shaped like a plate, having a size toclose the whole first opening portion 50. The lid portion 60 can shieldheat added to the optical connector 4 through the first opening portion50. The cover 6A also has a plurality of leg portions 62. The pluralityof leg portions 62 are provided at the opposite side edges of the lidportion 60 so as to extend in a direction intersecting with an innersurface 60 a of the lid portion 60, so that the cover 6A can be attachedto the bottom portion 56 of the adapter 5A. Each of the leg portions 62has an engagement portion 64. The engagement portion 64 includes aprotrusion on the leg portion 62. In an example shown in FIG. 1, a tapersurface 64 a forming the protrusion provides a protruding shape. Sincethe cover 6A has the engagement portions 62, the engagement portions 64are latched to the bottom portion of the adapter 5A when the cover 6A isattached to the adapter 5A. The lid 6A is held so as to cover theopening portion 50. It is preferable that the cover 6A is also formed ofa heat-resistant resin, desirably the same material as the adapter 5A.Other engagement portion set forth in this application may have the sameas shape of the engagement portion 64 of the leg portion 62, and theengagement portion 64 thereof may have a shape of the same as that ofanother engagement portion described in this application.

A protrusion 60 b (as shown in FIG. 5) is formed on the inner surface 60a of the cover portion 60. When the cover 6A covers the first openingportion 50, the optical connector 4 and the optical connector 7 isarranged between the protrusion 60 b and the mounting surface 56 a,whereby the optical connector 4 and the optical connector 7 arepositioned with respect to the vertical direction to the mountingsurface 56 a.

The connector 7A will be described with reference to FIGS. 1, 2 and 3A.The optical connector 7A comprises a ferrule 70, a spring 71, and aninsertion member 72. A coated optical fiber 76, the coating layer ofwhich is removed at its end portion, is connected to the opticalconnector 7A. The ferrule 70 is available for an MT connector, and thefilaments of the coated optical fiber 76 are arranged therein.

An elastic member, such as the spring 71, is adjacent to the ferrule 70.In the optical connector 7 shown in FIGS. 1 to 4, the coated opticalfiber 76 passes through the spring 71. The insertion member 72 isarranged so as to be adjacent to the spring 71. The insertion member 72Ahas a through hole through which the coated optical fiber 76 passes.Thus, with the coated optical fiber 76 inserted in this hole, theinsertion member 72 can move along the coated optical fiber 76.

The insertion member 72 includes a pair of arm portions 73. The armportions 73 extend from the respective side surfaces of the insertionmember 72 toward the ferrule 70. Each arm portion 73 includes anengagement portion 74 at its tip end. The engagement portion 74 islatched to the engagement portion 54 of the guide member 53. Aprotrusion 75 is arranged, on the upper surface of the insertion member72, along the optical axis of the optical connector 7 so as to beinserted into the adapter 5A along the axis 8. A groove 60 c (shown inFIG. 2) is provided on the lower surface 60 a of the cover portion 60.The protrusion 75 enables the groove 60 c to guide the optical connector7A. It is also possible to apply a recess instead of the protrusion 75and to apply a protrusion instead of the groove 60 c.

With reference to FIGS. 1 to 5, a procedure of connecting the opticalconnector 7 to the optical module product 9A will be described.

The optical connector 4 connected to the optical module 2, the adapter5A, the stopper 52, the guide member 53, and the cover 6A are combinedin the following sequence. With reference to FIG. 1, the opticalconnector 4 is moved in a direction indicating Arrow B toward theadapter 5A to be arranged on the mounting surface 56 a. The guide member53 is moved in a direction indicating Arrow C to be arranged on themounting surface 56 a so as to adjoin the optical connector 4. Next, thestopper 52 is moved in a direction indicating Arrow C and then isarranged while the stopper 52 positioned to the adapter 5A. Thisarrangement restricts the moving range of the optical connector 4.Subsequently, the cover 6A is moved in a direction indicating Arrow D tobe arranged so as to cover the optical connector 4. The cover 6A closesthe first opening portion 50, whereby the covers 6A protects the opticalconnector 4, the stopper 52, and the guide member 53.

When the first opening portion 50 of the adapter 5A is closed by thecover 6A, the adapter 5A and the cover 6A defines the insertiondirection of the optical connector 7A. That is, when the opticalconnector 7A is pushed in through the second opening portion 51, theoptical connector 7A is guided by the bottom portion 56 a, the pair ofwall portions 55, and the cover portion 60. The optical connector 4 andthe ferrule 70 are positioned to each other by the guide pins 40.

The optical connector 4 and the ferrule 70 are in contact with eachother, and then the optical connector 7A is further pushed in such thatthe spring 71 is pressed. The engagement portion 54 of the guide member53 is latched to the engagement portion 74 of the insertion member 72.The optical connector 4 and the optical connector 7 are held by anelastic returning force generated by the spring 71 with the engagementportions 54 and 74 latched to each other.

The stopper 52 restricts the range that the optical connector 4 in thisconnection, whereby an external force directly applied to the coatedoptical fiber 3 is decreased and the quality of the bend of the coatedoptical fiber 3 is also decreased. This prevents the coated opticalfiber 3 from being damaged. In mating them, force is not directlyapplied to the optical module 2.

Even if spacing (gap less than a millimeter) is provided between theoptical connector 4 and the guide member 53 or between the guide member53 and the stopper 52, there is no obstacle in practical use in matingthe optical connector 4 and the optical connector 7 with each other.

FIGS. 4 and 5 show the optical connector 4 and the optical connector 7Aaccommodated in the adapter 5A. After the optical connector 7A is matedto the optical connector 4, the coated optical fiber 76, connected withthe optical connector 7A, is stringed in securing portions 79 providedon a wiring base 78.

In order to attach the optical module 2 and other electronic parts tothe substrate 10, reflow soldering can be used. The coated optical fiber3 and the optical connector 4 both are not, however, heat-resistant. Inthe foregoing first embodiment, in order to protect them against heat inthe reflow soldering step, the protecting layer such as theheat-shrinkable tubing 30 protects the coated optical fiber 3. Theshielding member such as the lid portion 6A can also protect the opticalconnector 4 against heat.

According to the optical module mounting substrate product 1A and theoptical module product 9A of the first embodiment, the coated opticalfiber 3 is provided between the optical connector 4 and the opticalmodule 2, whereby force from the optical connector 4 is not directlyapplied to the optical module 2 in mating the optical connector 7A andthe optical connector 4 and unmating it therefrom. The optical module 2can be, therefore, kept in excellent characteristics for a long term.

Since the adapter 5A is provided for holding the optical connector 4therein, it is possible to mate the optical connector 7A to the opticalconnector 4 at a position apart from the optical module 2. That is, theadapter 5A can be arranged at a position appropriate for easily carryingout the mating operation, and the optical module 2 can be arranged at aposition suitable for connecting it with other electronic parts. Theoptical module 2 has a structure allowing the optical connector 4 tocouple the optical connector 7A through the coated optical fiber 3. Thisstructure permits the prompt mating, and can reduce restrictions on thedesign of the printed circuit board.

In a receptacle type optical module of a structure different from theoptical module product 9A and the optical module mounting substrate 10of this embodiment, since the module body has a connector portion, ithas been necessary for a region for mating an optical connector in thevicinity of the optical module. On this account, this region cannotmount other electronic parts thereon. However, in the present invention,such a region is not needed.

Both optical module 2 and adapter 5A are mounted on the substrate 10,and the optical connector 4 is held in the adapter 5A. Thisconfiguration can prevents the coated optical fiber 3 from being bentbetween the optical module 2 and the optical connector 4.

The adapter 5A has the first opening portion 50 and the second openingportion 51. Owing to these opening portions, the optical connector 4 canpass through the first opening portion 50, so that the optical connector4 can is arranged in the adapter 5A without damaging the coated opticalfiber 3, and the optical connector 7A can pass through the secondopening portion 51 in connecting, so that the optical connector 7A canbe mated with the optical connector 4.

The optical connector 4 is the push-on type optical connector, wherebythe connection is easily made by inserting the optical connector 7through the second opening portion 51.

The adapter 5A also has a stopper 52, which prevents the coated opticalfiber 3 from being bent by a force applied in connecting the opticalconnector 7A. This is particularly advantageous for the push-on typeoptical connector of the optical connector 4.

The stopper 52 can suppress the so-called ferrule back phenomenon. Whenthe ferrule back phenomenon occurs, the repelling force from the spring71 moves the optical connector 4 in a direction along the coated opticalfiber 3 while the optical connector 7A is mated to the optical connector4. When the coated optical fiber 3 cannot alleviate, by its bending, therepelling force applied to the optical connector 4, this phenomenonaffects the characteristics of the coated optical fiber 3.

There is a slight difference in the position of the optical connector 4accommodated in the adapter 5A depending on the respective assemblingaccuracy between the coated optical fiber 3 and the optical connector 4with respect to the optical module 2 and depending on the respectivemounting accuracy with respect to the substrate 10. When the length ofthe coated optical fiber 3 is about 30 mm, the position of the opticalconnector is shifted by, for example, about 1 mm with respect to theoptical axis direction. The position of the stopper 52 can be, however,adjusted, whereby the positional shifts can be compensated for by theadjusted position of the stopper 52. This is effective for reducing theoccurrence of the ferrule back phenomenon in the optical connector 4.

The adapter 5A comprises the positioning portions 55 e and 55 f providedon the inside surfaces 55 c and 55 d of the wall portion 55 to adjustthe attaching position of the stopper 52, whereby the positioningportions 55 e and 55 f provide the stopper 52 with easy positionaladjustment and prevent the optical connector 4 from moving. The finenessin the positional adjustment depends on the pitch of the recesses orprotrusions contained in the positioning portions 55 e and 55 f. Thisstructure provides the positional adjustment with high precision lessthan a millimeter. The simple structure results in the high reliability.

The lid 6A can hold the optical connector 4 tightly in place, so thatthe coated optical fiber 3 is prevented from bending. The lid 6A coversthe mated optical connector 4 to protect the optical connector 4 fromdust and from contact with surrounding electric parts. Further, sincethe lid 6A can protect the optical connector 4 from heat added inmanufacturing steps, it is useful for fabricating good-quality opticalmodules.

Since the coated optical fiber 3 is protected by the protecting layersuch as the heat shrinkable tubing 30, this protecting layer preventsthe coated optical fiber 3 from coming into direct contact withsurrounding electric parts and protects the coated optical fiber 3 fromheat in the reflow soldering step. Accordingly, it is possible tomanufacture the high quality optical module product and optical modulemounting substrate product. The coating layer can also raise therigidity of the coated optical fiber 3.

The heat shrinkable tubing 30 can adhere to the side surface of thecoated optical fiber 3 to form the protecting layer. Since the heatshrinkable tubing 30 is excellent in heat resistance, it is suitable forprotecting the coated optical fiber 3 from heat added in themanufacturing steps. The heat shrinkable tubing 30 can cover not onlythe boot 41 for the optical connector 4 but also the connecting portionto the optical module 2 in order to provide the protecting layer. Thecoated optical fiber 3 is likely to bend at the portions above. Thisprotecting layer is useful to suppress the bending of the coated opticalfiber 3 threat.

FIGS. 6 to 8 show various modifications of adapters applicable to theoptical module product of the first embodiment. With respect to theadapters shown in these drawings, the configurations or forms alreadydescribed above can be applied to the modifications below, and have thesame function and effect in the modifications.

An adapter 5B shown in FIG. 6 comprises a guide member 63, formedintegrally, which has function of both stopper 52 and guide member 53 inthe first embodiment. Engagement portions 63 d and 63 e are provided onboth side surfaces of a bridge portion 63 b connecting both arm portions63 a of the guide member 63. The adapter 5B of FIG. 6 also provides themuch same effect as the optical module product of the first embodiment.

In the adapter 5C shown in FIG. 7, the inner surface of the third wallportion 58 is used as a stopper. The adapter 5C shown in FIG. 7 canprovide much the same effect as the optical module product of the firstembodiment except that the position of the stopper (third wall portion58) can not be adjusted. The adapter 5C has a simpler configuration thanthat of the optical module product as shown in FIG. 6 in that theadapter 5C does not have any portions, such as an additional part of thestopper as well as the positioning portions 55 e and 55 f provided inthe adapter 5B shown in FIG. 6. However, the adapter 5C may have thepositioning portions 55 e and 55 f. The adapter 5C can be relocated onthe substrate, so that the optical connector 4 is also relocated withregard to the position of the optical module 2 on the substrate.

An adapter 5D shown in FIG. 8 does not include the stopper 52 as in thefirst embodiment. Besides, since the adapter 5D does not comprise thestopper, the positioning portions are also not provided on the innersurfaces of the pair of wall portions 55. The adapter 5D has a simpleconfiguration in these points. In the adapter 5D, the optical connector4 is secured to the guide member 53. The adapter 5D is suitable for aconfiguration that the coated optical fiber 3 has sufficient rigidityprovided by the protecting layer such as the heat shrinkable tubing 30.This is because the heat shrinkable tubing 30 can provide the adapter 5Dwith rigidity sufficient to protect it against a force applied in theoptical axis direction in mating the optical connector 7.

In the adapter 5D, a force can be applied to the optical module 2 in theoptical axis direction when a push-on type optical connector is mated tothe optical module 2. However, after the optical connector has beenmated, the guide member 53, engaged with the insertion member 72,receives the force, whereby the force is not directly applied to theoptical module 2. The coated optical fiber 3 can relieve other force,such as bending moment applied in the direction perpendicular to the topsurface of the substrate 10 in mating or unmating the optical connectoror bending moment caused by war page in the substrate 10, because of theprotecting layer 30, whereby the force is not exerted on the opticalmodule 2.

Although not particularly shown in the drawing, the guide member 53 maybe formed integrally with the adapter.

FIG. 9 is a view showing an adapter 5E. A pair of wall portions 55 a and55 b comprises guide grooves 551 and 55 m on outside surfaces 55 j and55 k (although they are provided on the outside surface 55 j, they donot appear in the drawing). The guide grooves 55 l and 55 m can guideleg portions 62 such that a lid 6 is arranged at a predeterminedposition. Each of the guide grooves 55 l and 55 m extends in a directionfrom one side of the outer wall surface 55 k to a bottom portion 56. Theguide grooves 55 l and 55 m also include fan grooves having the shape ofa sector in the vicinity of one side of the outer surface 55 k, andrectangular grooves adjoining the respective fan grooves. The fangrooves can easily guide the engagement portions 65 of the leg portions62 to the guide grooves, whereby the lid 6A is attached to thepredetermined position.

The adapter 5E is arranged on the substrate 10 (not shown), and thebottom portion 56 comprises one or more support portions 56 e extendingin a direction perpendicular to the bottom surface. The respectivesupport portions 56 e extend so as to provide a space between thesubstrate 10 and the bottom portion. The space provides a heatinsulating layer, adjacent to the support portion 56 e, by air.

Next, with reference to FIGS. 10 to 12, an optical module product 9B andan optical module mounting substrate product 1B of a second embodimentwill be described. The optical module product 9B of the secondembodiment comprises an adapter 5D and a lid 6B different from theadapter 5A and the lid 6A described in the first embodiment,respectively. Besides, the second embodiment provides an opticalconnector 7B different from the optical connector 7A of the firstembodiment.

As in the case of the first embodiment, the adapter 5D comprises a firstopening portion 50 opened to a direction vertical to a mounting surface55 a and a second opening portion 51 opened in an optical axis directionof an optical connector 4 provided in the adapter 5D. Since the opticalconnector 4 shown in the second embodiment is not used as a push-on typeconnector, the adapter 5D does not include the stopper 52, the guidemember 53 and the positioning portions 55 e and 55 f as shown in thestopper 5A of the first embodiment.

On the other hand, the adapter 5D has protrusions 55 g and 55 h onrespective inner surfaces of a pair of wall portions 55 a and 55 b inorder to position the optical connector 5 in both right and leftdirections with respect to the optical axis. Since the protrusions 55 gand 55 h are provided so as to guide the optical connectors 4 and 7B, aninterval between the pair of protrusions 55 g and 55 h is determined tobecome an interval slightly larger than the widths of the opticalconnectors 4 and 7B.

In the adapter 5D, the bottom portion 56 has support portions 56 eextending opposite to the wall portions 55 a and 55 b with respect tothe mounting surface 56 a. The supporting portions 56 e are arrangedbetween the substrate 10 and the bottom portion 56, and has a pluralityof supporting plates extending in a direction intersecting with thelongitudinal direction of the adapter 5D. The supporting portions 56 ehave predetermined height so as to provide an air gap between thesubstrate 10 and the bottom portion 56. This air gap is provided so asto decrease heat conduction from the substrate 10.

The adapter 5D has a projection 59 provided on each of the outsidesurfaces of the wall portions 55 a and 55 b. A pair of hinge pieces 66are provided at one end of the lid 6B. Each hinge piece 66 has a hingehole 66 a provided such that the protrusion 59 of the adapter 59 isinserted therein. When the hinge holes 66 a of the lid 6B are engagedwith the projections 59 of the adapter 5D, the lid 6B becomes rotatableabout an axis connecting the pair of projections 59. This configurationshows that the lid 6B is attached to the body of the adapter 5D so as toopen and close the first opening portion 50.

In the adapter 5D, the lid 6B covering the first opening portion 50 hassuch a size that it can cover the whole adapter 5D. The lid 6B has apair of leg portions 62 extending from both side edges. An engagementportion 64 is arranged at each tip end of the leg portions 62. When thelid 6B is disposed so as to cover the first opening portion 50, theengagement portions 64 are latched detachably to the bottom portion 56of the adapter 5D, remaining the latching state in which the lid 6Bcovers the first opening portion 50.

The lid 6B has a rectangular cut 68 provided between the pair of hingepieces 66. The cut 68 allows the lid 6B to sufficiently open even whenthe optical connector 4 is arranged in the adapter 5D.

The optical connector 7 of the second embodiment can be an MT connector.The MT connector has a ferrule 70 attached to a tip portion of a coatedoptical fiber 76. After the optical connector 4 and the opticalconnector 7B are mated with each other, an optical connector clip 80 isused to keep the optical connector 4 and the optical connector 7B mated.The optical connector clip 80 is attached and detached by use of anoptical connector clip tool 82 as shown in FIG. 11.

A procedure of connecting the optical connector 7B to the optical moduleproduct 9B will be described.

In accordance with a direction of Arrow F shown in FIG. 11, the opticalconnector 4 is placed on the mounting surface 56 through the firstopening portion 50. In accordance with a direction of Arrow G, theprotrusion 59 is inserted in the hinge hole 66 a such that the lid 6B isattached to the adapter 5D. Next, in accordance with Arrow H, theoptical connector 7B is inserted through the second opening portion 51,so that the mating surface of the optical connector 4 faces the matingsurface of the optical connector 7B. Thereafter, in accordance with adirection of Arrow J, the optical connector 4 and the optical connector7B is clamped by the optical connector clip 80 using the tool 82 withthe first opening portion 50 opened. Then, the lid 6B is closed as shownin FIG. 12.

Even if the lid 6B is opened or closed, the operation can be made suchthat the mating surface of the optical connector 4 faces the matingsurface of the optical connector 7B. The operation can be performedwhile making visual observations. Since the optical connector clip 80has to be attached in a subsequent step, in most cases, the connectors 4and 7B is mated while the lid 6B is opened.

The optical module product 9B shown in the second embodiment also haseffects similar to those of the optical module product 9A according tothe first embodiment except for effects relating to a point that theoptical connector 4 is not used as a push-on type optical connector.

The optical module product of the present invention is not limited tothe foregoing embodiments. For example, in the foregoing embodiments,although the substrate 10 is a printed wiring board in which wiring isprinted, it can be a plate-like member for only mounting the opticalmodule 2 and the adapters 5A to 5D. Besides, in the foregoingembodiments, although the first opening portion 50 continuously connectsthe second opening portion 51, these opening portions 50 and 51 can beprovided such that they are separated from each other. Further, in theforegoing embodiments, although the lid 6A or 6B can be attached to theadapters 5A to 5D, it can be directly attached to the substrate 10 so asto cover the first opening portion 50.

In the first embodiment, although the description has been made on thepush-on type optical connector wherein the optical connector 7A containsthe spring, the optical connector 4 may contain the spring, or both mayincorporate the spring. In the first embodiment, although the MTconnector is used to form the push-on type optical connector, thepush-on type optical connector can also be made using an MPO typeconnector.

A pigtail type optical module includes a coated optical fiber of severaltens cm or more extended from an optical module in which an opticalconnector is attached to the tip end of the coated optical fiber. Sincethe coated optical fiber has a sufficient margin of the length of thepigtail type optical module, the ferrule back phenomenon does not exertforce on the optical module and the coated optical fiber to cause achange in characteristics in mating the optical connectors. However, thepigtail type optical module requires a region on the substrate where thecoated optical fiber is arranged with the coated optical fiber tied in abundle. At this point, it is different from the optical module productof the present invention, which is advantageous for connecting theoptical connector on the substrate while the area for the optical fiberis saved.

In the pigtail type optical module like this, it is difficult to handlethe coated optical fiber in an assembling step for an optical module aswell as a part-mounting step therefor, it is also difficult to applyassembling automatization and a reflow soldering step. However, thepresent invention can improve the defects of this sort of pigtail typeoptical modules.

FIG. 13 is a schematic view showing a pair of optical module mountingsubstrate products of a third embodiment.

An optical module mounting substrate product 15 (16) comprises opticalmodules 2 a, 2 b, 2 c and 2 d (2 e, 2 f, 2 g and 2 h), adapters 5 a, 5b, 5 c and 5 d (5 e, 5 f, 5 g and 5 h), optical connectors 4 a, 4 b, 4 cand 4 d (4 e, 4 f, 4 g and 4 h), coated optical fibers 3 a, 3 b, 3 c and3 d (3 e, 3 f, 3 g and 3 h) for connecting the optical connectors 4 a, 4b, 4 c and 4 d (4 e, 4 f, 4 g and 4 h) to the optical modules 2 a, 2 b,2 c and 2 d (2 e, 2 f, 2 g and 2 h), respectively, and a substrate 10 asuch as a printed circuit substrate. The optical connectors 4 a, 4 b, 4c and 4 d (4 e, 4 f, 4 g and 4 h) are respectively connected to opticalconnectors 7 a, 7 b, 7 c and 7 d (7 e, 7 f, 7 g and 7 h). The opticalconnectors 7 a, 7 b, 7 c and 7 d are respectively connected to theoptical connectors 7 e, 7 f, 7 g and 7 h through coated optical fibers76 a, 76 b, 76 c and 76 d. One or more electronic parts 100 a to 100 dcan be mounted on the optical module mounting substrate product 15.

As described above, since the optical module mounting substrate product15 and the optical module mounting substrate product 16 have the samestructure, the following description will be made on the optical modulemounting substrate product 15.

The optical modules 2 a to 2 d are arranged so that one surface of eachof the optical modules 2 a to 2 d faces one side 10 c of the substrate,10 a, and the coated optical fibers 3 a to 3 d extend from the surfaceof each optical modules 2 a to 2 d. The adapters 5 a to 5 d are arrangedbetween the optical modules 10 a to 10 d and the one side 10 c. Theadapters 5 a to 5 d accommodates the optical connectors 4 a to 4 dconnected to one end of the coated optical fibers 3 a to 3 d, with theoptical axes of the optical connectors 4 a to 4 d directed to the oneside 10 c of the substrate 10 a.

In the optical module mounting substrate product 15, the opticalconnectors 4 a to 4 d and the other optical connectors 7 a to 7 d can bemated to each other on the side 10 c of the substrate 10 a. When theoptical connectors 4 a to 4 d are mated to the optical connectors 7 a to7 d in the adapters 5 a to 5 d, the connecting portions of theconnectors can be protected. The adapters 5 a to 5 d can also bedisposed so that the other optical connectors 7 a to 7 d are mated atrespective positions where the optical connectors 7 a to 7 d protrudefrom the one side 10 c of the substrate 10 a in part. In thisarrangement, even if a lid is provided so as to cover the substrate 10a, the adapters 5 a to 5 d can be arranged so as to protrude from theone side of the substrate 10 a. This arrangement facilitates theattachment of the connectors 7 a to 7 d.

In the optical module mounting substrate product shown in FIG. 13, whenthe optical connectors 7 a to 7 d are mated to the optical connectors 4a to 4 d, there is little force directly applied to the optical modules2 a to 2 d. On the other hand, the pigtail type optical module requiresa processing for tying the coated optical fiber together, connecting theoptical connector and the optical module, in order to mount the tiedcoated optical fiber on the substrate 10 a, and requires a region on thesubstrate where the bent coated optical fiber is disposed. The diameterof the bent coated optical fiber is about 40 mm. However, the opticalmodule mounting substrate product 15 eliminates both this processing andthe region. The distances between the optical modules 2 a to 2 d and theadapters 5 a to 5 d to can be less than 40 mm. In this embodiment, thedistance is set to 30 mm. When the optical connectors 4 a to 4 d aredisposed in the adapters 5 a to 5 d in view of allowable curvature ofthe coated optical fibers 3 a to 3 d, the minimum value of this intervalcan be estimated to be 10 mm.

Since the foregoing processing becomes unnecessary, it is possible toarrange the plurality of optical modules 2 a to 2 d along the one side10 c of the substrate 10 a in a line. Besides, the arrangement densityof the optical modules 2 a to 2 d can be enhanced without limitation bythe above region. Since the adapters 5 a to 5 d comprise the secondopening portions 51, the mating of the optical connectors 7 a to 7 d canbe easily made even if a number of optical modules are arranged to beadjacent to each other.

In this embodiment, one side 10 c of the substrate 10 a has theeffective size of 280 mm, and the width of the optical module has theeffective size of 16 mm. Owing to the sizes, 16 optical modules can bedisposed in parallel with the one side 10 c of the substrate 10 a.Accordingly, it is possible to secure 8 channels for each oftransmission and reception, each having a transmission capacity of 2.4Gbit per channel, and if the optical modules are mounted on thesubstrate with one side of 300 mm at high density, a transmissioncapacity of 160 Gbit can be secured. This value, however, depend on atransmission capacity per channel.

INDUSTRIAL APPLICABILITY

As described above, the adapter of the present invention includes thewall portions on the mounting surface. In the adapter, the first opticalconnector can be moved in the direction vertical to the mountingsurface, and the second optical connector can be moved along thepredetermined axis. On this account, the second connector can beinserted along the predetermined axis toward the housed first opticalconnector. Since the second optical connector is mated to and unmatedfrom the first optical connector in this adapter, force applied to theoptical module is decreased in mating and unmating the connector.

The optical module product of the present invention may be provided withthe adapter, the coated optical fiber and the optical connector. Theoptical connector is housed in the adapter. Accordingly, the adapter canhold the optical connector attached to one end of the coated opticalfiber extending from the optical module. This can decrease magnitudes ofvarious forces such as a bending force to the coated optical fiber.

The optical module mounting substrate product of the present inventionis provided with one or more optical module products and the substrate.The optical module and the adapter are attached onto the substrate.Since the second optical connector is mated to and unmated from thefirst optical connector housed in the adapter, even if the opticalmodule is connected to one end of the first connector, the adapterprevents force, applied to the optical module, from being directlyapplied to the optical module in mating and unmating. This arrangementcan prevent characteristics of the optical module from changing by theforce, and enables the optical module to keep excellent characteristicsfor a long term.

Accordingly, there are provided the adapter in which force applied tothe optical module can be decreased when the coated optical fiber isdetached and attached, the optical module product including theconnector, and the optical module mounting substrate on which theoptical module product is mounted.

What is claimed is:
 1. An adapter for connecting a first opticalconnector to a second optical connector, the first optical connector andthe second optical connector being aligned with each other by means of aplurality of guiding pins, each optical connector including an opticalfiber, comprising: a bottom portion having a mounting surface formounting first and second optical connectors, said mounting surfaceextending in a direction of an optical axis of the optical fiber; andfirst and second wall portions provided on the mounting surface, thefirst and second wall portions having their respective inner wallsurfaces faced to each other, the inner wall surfaces extending in adirection of the optical axis to guide at least one of the first andsecond optical connectors between the inner wall surfaces, and the firstand second wall portions extending in the direction of the optical axis;wherein the bottom portion and the first and second wall portions arearranged to provide a first opening portion and a second openingportion, the first opening portion being provided so as to receive thefirst optical connector, the first opening portion opening in adirection normal to the mounting surface, the second opening portionbeing provided so as to receive the second optical connector, and thesecond opening and the second opening portion opening in the directionof the optical axis.
 2. The adapter according to claim 1, furthercomprising a stopper for restricting a position of a guide member of thefirst optical connector in the direction of the optical axis.
 3. Theadapter according to claim 2, further comprising positioning means foradjusting a position of the stopper in the direction of the opticalaxis.
 4. The adapter according to claim 2, further comprising at leastone of a recess and a protrusion, provided on each of the inner wallsurfaces of the first and the second wall portions, for enabling aposition of the stopper to be adjusted in the direction of the opticalaxis.
 5. The adapter according to claim 1 further comprising a thirdwall portion extending in a direction intersecting with the opticalaxis, said third wall portion being connected with the first and secondwall portions and the bottom portion; wherein the third wall portionincludes a cut provided for receiving an optical fiber connected to oneof the first and second connectors.
 6. The adapter according to claim 1,further comprising a lid supported by the first and the second wallportions, said lid being provided so as to face the mounting surface. 7.The adapter according to claim 1, wherein the bottom portion has a latchportion and an opposed surface, the opposed surface being opposed to themounting surface, the latch portion extending from the opposed surfacein a direction normal to the opposed surface.
 8. An optical moduleproduct comprising: said adapter according to claim 1; an optical modulefor performing at least one of a conversion of a conversion from anelectrical signal into an optical signal and a conversion from anoptical signal into an electrical signal; a coated optical fiberincluding a first end portion connected to the optical module and asecond end portion; and an optical connector accommodated in theadapter, said optical connector being connected to the second endportion of the coated optical fiber, said optical connector having aplurality of holes for receiving guiding pins.
 9. An optical moduleproduct comprising: said adapter according to claim 2; an optical modulefor performing at least one of a conversion from electrical signals intooptical signals and a conversion from optical signals into electricalsignals; a coated optical fiber including a first end portion connectedto the optical module and a second end portion; and an opticalconnector, accommodated in the adapter, connected to the second endportion of the coated optical fiber, said optical connector having aplurality of holes for receiving guiding pins.
 10. An optical moduleproduct comprising: said adapter according to claim 3; an optical modulefor performing at least one conversion of a conversion from electricalsignals into optical signals and a conversion from optical signals intoelectrical signals; a coated optical fiber including a first end portionconnected to the optical module and a second end portion; and an opticalconnector, accommodated in the adapter, said optical connector beingconnected to the second end portion of the coated optical fiber, saidoptical connector having a plurality of holes for receiving guidingpins.
 11. An optical module product comprising: said adapter accordingto claim 4; an optical module for performing at least one conversion ofa conversion from electrical signals into optical signals and aconversion from optical signals into electrical signals; a coatedoptical fiber including a first end portion connected to the opticalmodule and a second end portion; and an optical connector accommodatedin the adapter, an optical connector being connected to the second endportion of the coated optical fiber, said optical connector having aplurality of holes for receiving guiding pins.
 12. An optical moduleproduct comprising: said adapter according to claim 5; an optical modulefor performing at least one conversion of a conversion from electricalsignals into optical signals and a conversion from optical signals intoelectrical signals; a coated optical fiber including a first end portionconnected to the optical module and a second end portion; and an opticalconnector accommodated in the adapter, said optical connector beingconnected to the second end portion of the coated optical fiber, saidoptical connector having a plurality of holes for receiving guidingpins.
 13. An optical module product comprising: said adapter accordingto claim 6; an optical module for performing at least one conversion ofa conversion from electrical signals into optical signals and aconversion from optical signals into electrical signals; a coatedoptical fiber including a first end portion connected to the opticalmodule and a second end portion; and an optical connector accommodatedin the adapter said optical connector being connected to the second endportion of the coated optical fiber, said optical connector having aplurality of holes for receiving guiding pins.
 14. The optical moduleproduct according to claim 9, wherein the coated optical fiber has aprotecting layer thereon.
 15. The optical module product according toclaim 14, wherein the protecting layer includes a heat shrinkable tubingadhered to a side surface of the coated optical fiber.
 16. An opticalmodule mounting substrate product comprising: one or more optical moduleproducts each including an optical module, a coated optical fiber, anoptical connector and an adapter for connecting another connector to theoptical connector; the optical connector and the other optical connectorbeing aligned with each other by means of a plurality of guiding pins;and a substrate including a conductive wiring layer, the optical moduleand the adapter being mounted to said substrate; wherein the coatedoptical fiber includes a first end portion connected to the opticalmodule and a second end portion connected to the optical connector;wherein the adapter includes first and second wall portions and a bottomportion having a mounting surface, said mounting surface extending in adirection of an optical axis of the second end portion of the opticalfiber, the mounting surface being provided for mounting thereon theoptical connector, the first and second wall portions being arranged onthe mounting surface at opposite two sides of the bottom portion, thefirst and second wall portions extending a direction of the opticalaxis; the first and second wall portions having their respective innerwall surfaces, and the inner wall surfaces extending in a direction ofthe optical axis to guide at least one of the optical connector and theother optical connector between the inner wall surfaces; the bottomportion and the first and second wall portions are arranged to provide afist opening portion and a second opening portion, said first openingportion being provided so as to receive the first optical connector,said first opening portion opening in a direction normal to the mountingsurface, said second opening portion being provided so as to receive theother optical connector, and said second opening portion opening in apredetermined axis direction; and wherein the optical connector isaccommodated in the adapter.
 17. The optical module mounting substrateproduct according to claim 16, wherein an interval between the opticalmodule and the adapter is not less than 10 mm and not larger than 40 mm.18. The optical module mounting substrate product according to claim 16,wherein the optical module, the optical connector, the coated opticalfiber, the adapter are arranged in a direction of an optical axis of theoptical module product.
 19. The optical module mounting substrateproduct according to claim 16, wherein the number of the optical moduleproducts, each arranged along one side of the substrate, is sixteen.